WASHINGTON — Grand jury transcripts released yesterday from the biggest espionage case of the Cold War raise questions whether Ethel Rosenberg was convicted and executed based on perjured prosecution testimony.

The Rosenbergs were convicted of passing nuclear weapons secrets to the Soviet Union and were electrocuted in 1953. Since then, decrypted Soviet cables have appeared to confirm that Julius Rosenberg was a spy, but doubts have remained about Ethel Rosenberg’s role.

At the Rosenbergs’ trial, the key testimony against Ethel Rosenberg came from her brother and sister-in-law, David and Ruth Greenglass.

They testified that Ethel Rosenberg had typed stolen atomic secrets from notes provided by David Greenglass. The testimony provided the direct involvement the jury needed to convict and that the judge in the case needed to sentence Ethel Rosenberg to death.

In recent years, David Greenglass recanted his testimony about the typing.

On Thursday, historians spotted a major omission in Ruth Greenglass’s newly released grand jury testimony preceding the trial. Nowhere in the grand jury testimony does Ruth Greenglass tell the story about seeing Ethel Rosenberg type up the secrets.

In fact, in her grand jury testimony, Ruth Greenglass says that she herself wrote out the secrets in longhand. That testimony is consistent with the subsequently decrypted Soviet cables from the time in which the Soviets described material received from the Rosenbergs as being in longhand.

The grand jury testimony from Ruth Greenglass confirms that the trial testimony about typing is a complete fabrication, said Georgetown University law professor David Vladeck, part of the team of lawyers and historians who succeeded in gaining public release of the transcripts.

“The Rosenberg case illustrates the excesses that can occur when we’re afraid,” said Meredith Fuchs, general counsel to the National Security Archive, one of the private groups that fought in court for the release of the grand jury material.

“In the 1950s, we were afraid of communism; today, we’re afraid of terrorism; we don’t want to make the same mistakes we made 50 years ago,” Ms. Fuchs said.

The newly released grand jury material discloses that nearly four dozen witnesses testified to the grand jury, of whom only four testified at the Rosenbergs’ trial. Among those who did not testify at the trial but did testify to the grand jury were a man and wife who the FBI believed were Soviet agents.

They were never charged, however, and the transcripts show that prosecutors made no effort to question any of the grand jury witnesses about a series of stolen American non-nuclear defense secrets that the government felt many of the witnesses knew about.

The stolen secrets included proximity fuses used by the Soviets to shoot down the U-2 spy plane of Francis Gary Powers, one of the Cold War’s most explosive events.

The government also had evidence that the Rosenberg ring gave the Soviets secrets about airborne radar, land-based radar, analog computers used for guiding anti-aircraft weapons and information for the first designs of American jet engines, said Steve Usdin, an author who helped win release of the grand jury material.

Why did the grand jury not delve into the theft of non-nuclear secrets?

“I think that discussion of all of these other secrets that they gave the Soviets probably would have caused a great deal of alarm among the public and would have raised questions about the competence of American counterintelligence,” Mr. Usdin said.